对2取余数，结果为0，就是偶数，加一起就行了

n=int(input())
nums = list(map(int, input().split()))
sum = 0
for i in nums:
    if i%2==0:
        sum+=i
print(sum)

#include<bits/stdc++.h>
using namespace std;

signed main(){
    int n,ans=0,x;
    cin>>n;
    while(n--){
        cin>>x;
        if(!(x%2)) ans+=x;
    }
    cout<<ans<<endl;
}